1. Field of the Invention
The present invention relates, generally, to shutter assemblies for vehicles and, more specifically, to an active grille shutter for a vehicle and to a shutter subassembly for use with an active grille shutter for a vehicle.
2. Description of the Related Art
Grille shutters are used in connection with regulating airflow towards one or more heat exchangers used in connection with a powertrain of a vehicle, such as an automotive passenger vehicle. Heat exchangers are commonly used to regulate the temperature of various fluids circulated in internal combustion engines, whereby heat is typically removed from the fluid as it flows through the heat exchanger as cooler ambient air flows across the heat exchanger from a fan or as the vehicle travels at speed. Heat exchangers are realized in different ways and are used to cool correspondingly different types of fluid. By way of example, the heat exchanger may be realized as a radiator employed to cool engine coolant, an oil cooler employed to cool lubricating oil in the engine or transmission, an intercooler employed to cool charge air from a turbocharger or supercharger, a condenser employed to cool refrigerant in an air conditioning system, and the like.
Conventional grille shutters include a frame with a grille opening positioned adjacent to the heat exchanger and through which ambient air is taken in, and a plurality of shutters or fins disposed in the grille opening to be opened or closed. Here, the grille shutter typically includes a plurality of fins which are supported on shafts and which rotate concurrently about the shafts via connection with an interlocking arm. The interlocking arm, in turn, is connected to a link mechanism driven by an actuator in order to rotate the fins so as to open or close the grille opening.
Under certain vehicle operating conditions, such as at engine startup and during engine warmup, the fins may be rotated so as to block or otherwise restrict airflow to heat exchangers, such as the engine radiator, in order to decrease engine warmup time which, in turn, promotes reduced fuel consumption and improved emissions. Similarly, grille shutters are used to modify airflow to heat exchangers when the vehicle is traveling at speed, whereby aerodynamic drag can be reduced by rotating the fins so as to divert airflow away from the heat exchanger, thereby further contributing to increased fuel efficiency and improved emissions. Furthermore, grille shutters can be used to improve airflow across heat exchangers under certain vehicle operating conditions, such as during idle in hot ambient conditions where the fins can be opened so as to promote maximum airflow across the heat exchanger.
One disadvantage with conventional grille shutters is that they frequently employ link mechanisms and actuators which are complex to manufacture and which are typically exposed to debris and environmental contaminants. In addition, conventional grille shutters often necessitate that the fins flex or bend significantly in order to allow them to be installed to the frame, which complicates assembly and may require increased clearances to be provided between certain components. Here, increased tolerances can result in rattles or other noise generation during use under certain operating conditions.
Moreover, in certain vehicle applications, the fins can be relatively large and may require correspondingly large tooling for manufacturing. Thus, while grille shutter assemblies known in the related art have generally performed well for their intended use, there remains a need in the art for a grille shutter assembly with improved durability, which performs consistently under different vehicle operating conditions, and which promotes ease of assembly while, at the same time, reducing the cost of manufacturing the components of the grille shutter assembly.